Phytoremediation of Airborne Particulate Matter in Indoor Environments

Abstract

This research is motivated by the urgent need to protect people from the adverse health effects of PM2.5 (particles smaller than 2.5 μm in size) exposure by using potted plants as air filters in indoor environments. We quantified the ability of three different plant species for removing airborne particles by conducting experiments in an environmentcontrolled chamber. The plants selected were Christmas plant (Araucaria heterophylla, a needleleaved plant), Ficus plant (Ficus retusa, a small-leaved plant), and Croton plant (Codiaeum variegatum, a broad-leaved plant). The particle deposition velocities ranged from (32.4±10.6 to 41.0±10.8) cm/h for the Christmas plant, (0.6±1.6 to 2.53±3.27) cm/h for the Ficus plant, and (−0.09±3.8 to 6.07±6.28) cm/h for the Croton plant, depending on the particle size. On extrapolating those results to a small residential room, we found that 35–44 Christmas plants (the most effective species) would be required for reducing the steady-state PM2.5 concentration by 10% at an air exchange rate of 0.5 h−1.